Promoting effect of N₂ calcination on FeCeO_x for selective catalytic reduction of NO_x with NH₃

Abstract BACKGROUND Selective catalytic reduction of NO x with NH 3 (NH 3 ‐SCR) technology is effective for NO x removal. Acidity and redox ability are two significant characteristics for NH 3 ‐SCR catalysts. This study investigated the effects of N 2 calcination on the NH 3 ‐SCR performance of FeCeO x , inspired by the promotion of active oxygen species with inert atmosphere calcination. The structure‐activity relationship and reaction mechanism of the two catalysts (Fe 9 CeO x ‐N 2 and Fe 9 CeO x ‐air) were concluded based on the results of characterization. RESULTS Fe 9 CeO x ‐N 2 showed better NO x conversion and SO 2 resistance than Fe 9 CeO x ‐air, especially in low and medium temperature range. For fresh catalysts, a higher amount of O α , Fe 3+ and Ce 3+ promoted the redox ability of Fe 9 CeO x ‐N 2 , and further improved the NO x adsorption and activation. Additionally, the greater number of acid sites of Fe 9 CeO x ‐N 2 was another reason for its competitive performance. For SO 2 ‐poisoned catalysts, the primary reaction pathway was the reaction between pre‐adsorbed NH 3 species and NO x . The higher amount of acidity from metal sulfate contributed to its better SO 2 tolerance of Fe 9 CeOx‐N 2 . CONCLUSION Higher redox ability and acidity led to better NH 3 ‐SCR activity and SO 2 tolerance of Fe 9 CeO x ‐N 2 . This study provides a feasible preparation method for enhancing the NO x conversion and SO 2 tolerance of NH 3 ‐SCR catalysts. © 2023 Society of Chemical Industry.